Zou Shiming will need to "eat like a champion" if he wants to become one, warned trainer Freddie Roach, after a pre-fight snack that almost cost him dearly in his second professional fight on Saturday. Roach was annoyed after Zou ate a candy bar that sent his blood sugar soaring then crashing at the Venetian CotaiArena, leaving him running on empty. "He was a bit tired towards the end of the fight, but we have to pay more attention to his diet and pay more attention to what he eats," said Roach, who had a serious talk with Zou after the fight. "I saw him eat a candy bar and I was a bit upset by that. We know how George [former two-time heavyweight champion Foreman] and the amateurs like to eat candy bars, but that's for 12-year-olds. Overall I was pleased by his performance and we are heading in the right direction." Zou said he had made a grave error in judgment before the fight by refusing to eat a bowl of rice, which would have given him the energy to last the six rounds in his unanimous decision against tough Mexican teenager Juan Ortega in Fists of Gold II. "I didn't want it because I wanted to keep myself light before the fight and that was a lesson learnt," Zou, 32, said. They were lessons that were learned and I know exactly what I have to do Zou Shiming "After the fight, Freddie had a very serious talk with me. He told me, 'If you want to be a champion, you not only have to train like a champion, but you must eat like a champion'." "I'm pleased with the win. I'm still a newcomer to pro boxing but I am taking all this experience in. They were lessons that were learned and I know exactly what I have to do. My goal is to become world champion so I know all the new challenges I have to face. I need to face new fights. But I will work even harder." Zou had improved from his first professional bout in April, but still tended to fight like an amateur. He was exhausted by the end and was not able to string together a combination to hurt his opponent. Roach said: "It has to come a little bit quicker [the learning curve]. He's a two-time Olympic gold medallist, everybody in the world knows that. He had a tough guy in front of him today. There were exchanges, and he got hit back. Some things he has to pick up." Roach said training with Filipino great Manny Pacquiao in the Philippines in October could be a wake-up call. "It will be a real big lesson for Shiming. Pacquiao works out like a world champion. Zou is going to see what it takes to become a world champion. It's going to be a great learning curve for him [Zou]," he said. Roach said if Zou's stamina and power improved, he would move his protégé to eight-round contests as he progressed to a higher level, and seek out tougher opponents.